1. Field of the Invention
The invention herein relates to an exercise device and more particularly to an upper and lower body exercise device which can be used as an aerobic training device and also a high resistance muscle building exercise machine.
2. Overview of Prior Art
It is a commonly known that regular exercise is linked to increased health and increased life expectancy. With today's automated lifestyles regular physical exercise is something that most people must consciously add to their daily activities. To make the most productive use of the person's time the design of particular machines are used to facilitate this process in a safer manner. For most people, much of the underlining goal is to reduce body fat. To do this the greatest amount of work must be accomplished by the exercising person. This will invariably utilize the larger muscle groups in the body, which include the legs. An optimal design will include the ability to exercise both aerobically at a low intensity for a long period of time and anaerobically at a high intensity for a shorter period of time and the device should be fun to use. If the person does not enjoy using the machine, it will inevitably end up in the garage.
Several factors predispose such a product to success or failure. One such desirable trait is the ability to be made lightweight and inexpensive enough for the home market. Habling et al. in U.S. Pat. No. 5,366,432 disclosed a leg press machine in which the larger muscles of the legs and hips are utilized but the relative size and expense of such a device limits its use predominantly to a gym. In addition there is no means of working any upper body exercises on this design.
Hess in U.S. Pat. No. 5,279,530 discloses a home unit that works the leg muscles of the user. The problems include the resistance means, which is limited to an elastic cord that is not easily adjustable. In addition, the pedals are on linear tracks and therefore their movement lacks a realistic representation of natural body movement. It has been determined by a biomechanical model by Abelbeck in "An Evaluation and Optimization Model for Exercise Machines which Simulate Stair Climbing" that a gentle arc is preferred in simulating the most natural movement of the extension of the hip and knee. Also, the "fun" aspect has been totally removed from this device. One of the important features of an enjoyable physical activity of this sort is stimulation of the senses and particularly the Vestibular Apparatus in the inner ear. This pleasurable feeling which accompanies swinging or rocking in a rocking chair takes place from two aspects, linear acceleration associated with starting and stopping as well as rotational acceleration that accompanies a change in direction. In many designs, including the Hess patent, the head is stationary and therefore totally void of such stimulation.
Start and stop movement as well as minimal rotational acceleration is provided in the disclosure of Nichols in U.S. Pat. No. 5,108,095. The bulky size and associated expense minimize the effectiveness of such products in the home marketplace. In addition to the lack of upper body training, the minimum resistance provided is the user's body weight plus the weight of the machine. This would greatly limit the usefulness of an aerobic activity to only those in top physical condition. Therefore, the minimal angular acceleration felt by the user due to the use of a four bar linkage in which the upper body does not rotate with respect to the world is of little consequence since few people would be physically capable of a prolonged use of the machine anyway.
Designing a machine to conform to the body is paramount in importance in the world of exercise equipment. Variations from natural movements not only make the device less than effective, but injuries can occur from degeneration of connective tissue from repeated movements that are atypical to the body. The variation in resistance to the muscles as it applies to the muscles capability to perform work is addressed by Maag in U.S. Pat. No. 4,828,254. The resistance to the muscles of the legs is increased by mechanical means in accordance with the increased capacity of the body as the legs approach full extension relative to a flexed position. Here, as with the Nichols patent, lesser resistance to accommodate prolonged, repetitive movement is not practical for the majority of the users. Also, the physical size and the use of weights to make it effective limit this device to an anaerobic activity in a gym.
The ROCKIT produced by SOLOFLEX is designed to be used as an aerobic training device, but failed to account for biomechanical strength potentials in lifting the body on a simple linkage as shown in the literature. With the pivot point behind and below the body the resistance moment arm decreases as the platform pivots back. This is just the opposite of the strength potential of the body. The application of the spring resistance helps to overcome this but varies in contribution with the level of spring resistance. Additionally the lack of upper body conditioning makes this a less than adequate device.
The HEALTH RIDER offers some of the advantages as stated as desirable, as are illustrated by Smith in U.S. Pat. Des. Nos. 344,112 and 356,127. The benefits include the vestibular stimulation as making it fun to use, but it falls short in functionality due to unnatural movement and excessive strain on the lower back during the movement. This can be seen in the literature which illustrates that the handle for the arm movement is pulled in toward the midsection of the body at the end of the movement. Without any trunk support, this creates a disproportionately high stress on the lower back muscles and associated structures as compared to other major muscles such as the legs. This not only greatly limits the functionality of the device but predisposes the user to degenerative overuse of an already common problem area in the general public, low back pain from overuse. Thus for some persons who are physically able to use this device, they shouldn't. Their health risk is greater than their potential health benefit.